1. Field of the Invention
The present invention relates to an energy store for a photovoltaic system, an energy storage power plant, a control device, and a method for operating an energy store.
2. Description Of The Related Art
Conventional electrical power grids are based on a few centralized power plants which supply the end consumers with the aid of the installed transmission and distribution networks. This traditional system has served society well in providing a stable and reliable power supply. However, the increasingly intense political and environmental pressure to expand the use of renewable energy sources requires a new model of supplying power. This new power supply system must be flexible and intelligent so that is able to deliver quantities of power of any quality and magnitude from the various sources, and to control these as needed so that a reliable supply to the consumers is ensured at all times.
In the past, research and development has concentrated primarily on environmentally friendly power generation and intelligent measuring and information technology. However, it is becoming increasingly clear that for an optimal power supply, use should also be made of an energy store that is able to temporarily store power from renewable energies and feed it into the power grid as needed.
Based on service life considerations, an energy store should be operated only in certain states of charge (SOC) or within a charging window. Depending on the type of energy store, there are low and/or high states of charge in which the energy store should not be operated. Typical values are approximately 20% to 50% of nominal capacity, depending on the battery type.
Published German patent application document DE 10 2010 062 698 A1 relates to a photovoltaic module and a method for controlling a photovoltaic module. This photovoltaic module, having a connection for the direct energy supply to a customer, includes a controller having a switch for activating and deactivating the direct power supply. The controller also includes a telecommunication module which is coupled to the switch and is dialable by the customer via telephone, the telecommunication module being designed to control the switch and to allow activation and deactivation of the power supply as needed.